adds exportglobal function to util.sh that will export an environment variable to current shell and all future shells (there is also an loadenv function to load the global env variables into all older shells (I seem to have a lot of shells open, though it seems impractical to have PS1 source the file, it would be cool to have older shells automatically pick up the changes). Also adds the go.sh script that currently only has goenv function that uses the new exportglobal to set the GOPATH